/* ═══════════════════════════════════════
   MATHS EXAM PREP — Global Styles
═══════════════════════════════════════ */
:root {
  --primary:   #4f46e5;
  --primary-h: #4338ca;
  --success:   #16a34a;
  --success-h: #15803d;
  --danger:    #dc2626;
  --warning:   #d97706;
  --bg:        #f0f4ff;
  --card-bg:   #ffffff;
  --text:      #1e1b4b;
  --muted:     #6b7280;
  --radius:    14px;
  --shadow:    0 4px 24px rgba(79,70,229,.12);
  --font:      'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
}

/* ── SCREENS ── */
.screen { display: none; }
.screen.active, .screen:not([hidden]) { display: block; }

/* ── BUTTONS ── */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  padding: 10px 22px; border: none; border-radius: 10px;
  font-size: 1rem; font-weight: 600; cursor: pointer; transition: all .18s;
}
.btn:active { transform: scale(.97); }
.btn-primary  { background: var(--primary); color: #fff; }
.btn-primary:hover  { background: var(--primary-h); }
.btn-success  { background: var(--success); color: #fff; }
.btn-success:hover  { background: var(--success-h); }
.btn-secondary { background: #e0e7ff; color: var(--primary); }
.btn-secondary:hover { background: #c7d2fe; }
.btn-learn {
  background: #ecfeff; color: #0f766e; border: 2px solid #99f6e4;
}
.btn-learn:hover { background: #cffafe; }
.btn-large { padding: 14px 32px; font-size: 1.1rem; border-radius: 12px; }
.btn:disabled { opacity: .45; cursor: not-allowed; transform: none; }

/* ══════════════════════════════════════
   SETUP SCREEN
══════════════════════════════════════ */
#setup-screen {
  display: none; align-items: center; justify-content: center;
  min-height: 100vh; padding: 24px;
}
#setup-screen.active {
  display: flex;
}
.setup-card {
  background: var(--card-bg); border-radius: 20px; box-shadow: var(--shadow);
  padding: 40px 36px; max-width: 560px; width: 100%; position: relative;
}
.setup-history-link {
  position: absolute; top: 14px; right: 18px;
  font-size: .72rem; color: var(--muted); text-decoration: none;
  opacity: .85;
}
.setup-history-link:hover { text-decoration: underline; opacity: 1; }
.logo { font-size: 3rem; text-align: center; margin-bottom: 8px; }
h1 { text-align: center; font-size: 1.9rem; color: var(--primary); margin-bottom: 4px; }
.subtitle { text-align: center; color: var(--muted); margin-bottom: 28px; }

.form-group { margin-bottom: 18px; }
.form-group label { display: block; font-weight: 600; margin-bottom: 6px; font-size: .92rem; }
.form-row { display: flex; gap: 16px; }
.form-group.half { flex: 1; }
.setup-actions { display: flex; flex-direction: column; gap: 12px; }

input[type="text"], input[type="number"] {
  width: 100%; padding: 10px 14px; border: 2px solid #c7d2fe;
  border-radius: 10px; font-size: 1rem; color: var(--text);
  background: #f8f9ff; transition: border-color .2s;
}
input:focus { outline: none; border-color: var(--primary); background: #fff; }

.topic-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(170px, 1fr)); gap: 8px;
  max-height: 200px; overflow-y: auto; padding: 6px;
  border: 2px solid #e0e7ff; border-radius: 10px; background: #f8f9ff;
}
.topic-checkbox { display: flex; align-items: center; gap: 8px; font-size: .88rem; cursor: pointer; }
.topic-checkbox input { width: 16px; height: 16px; cursor: pointer; accent-color: var(--primary); }
.error-msg { color: var(--danger); font-size: .9rem; text-align: center; margin-top: 10px; }
.success-msg { color: var(--success); font-size: .95rem; text-align: center; margin-top: 10px; font-weight: 500; }
#start-btn { width: 100%; margin-top: 10px; }
#learn-topics-btn { width: 100%; }

/* ══════════════════════════════════════
   STUDY MODE
══════════════════════════════════════ */
#study-library-screen, #study-topic-screen, #study-concept-screen { padding: 24px 16px 48px; }
.study-card { max-width: 1080px; }
.study-library-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 16px;
}
.study-topic-button {
  display: flex; flex-direction: column; align-items: flex-start; gap: 10px;
  width: 100%; padding: 18px; border: 2px solid #dbeafe; border-radius: 16px;
  background: #f8fbff; color: var(--text); cursor: pointer; text-align: left;
  transition: transform .18s ease, box-shadow .18s ease, border-color .18s ease;
}
.study-topic-button:hover {
  transform: translateY(-2px); border-color: #93c5fd; box-shadow: var(--shadow);
}
.study-topic-button-icon { font-size: 1.8rem; }
.study-topic-button-title { font-size: 1.05rem; font-weight: 800; color: var(--primary); }
.study-topic-button-text { color: var(--muted); line-height: 1.5; font-size: .92rem; }
.study-topic-button-link { font-weight: 700; color: #0f766e; font-size: .9rem; }

.study-topic-card { max-width: 1120px; }
.study-visual-panel {
  background: var(--card-bg); border-radius: var(--radius); box-shadow: var(--shadow); padding: 20px;
}
.study-topic-card .study-visual-panel {
  padding: 22px;
}
.study-visual-panel-full {
  margin-bottom: 24px; padding: 24px;
}
.study-topic-visual {
  width: 100%; min-height: 220px; display: flex; align-items: center; justify-content: center;
}
.study-topic-visual svg { width: 100%; height: auto; max-width: 440px; }
.study-topic-card .study-topic-visual {
  min-height: 236px;
}
.study-topic-card .study-topic-visual svg {
  max-width: 460px;
}
.study-topic-visual-full {
  min-height: 280px; align-items: stretch;
}
.study-topic-visual-full svg {
  max-width: none; width: 100%; min-height: 260px;
}
.study-topic-card .study-topic-visual.study-topic-visual-full svg {
  max-width: none;
  width: 100%;
}
.study-intro-panel { margin-bottom: 0; }
.study-copy { color: #334155; line-height: 1.7; font-size: 1rem; }
.study-section-head { margin-bottom: 16px; }
.study-section-copy { color: var(--muted); line-height: 1.6; margin-top: 8px; }
.study-key-idea {
  margin-top: 16px; padding: 14px 16px; border-radius: 12px; background: #eef2ff; color: var(--text);
  border-left: 5px solid var(--primary); line-height: 1.6;
}
.study-concept-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 16px;
}
.study-concept-button {
  display: flex; flex-direction: column; align-items: flex-start; gap: 10px;
  width: 100%; padding: 18px; border: 2px solid #fbcfe8; border-radius: 16px;
  background: #fff7fb; color: var(--text); cursor: pointer; text-align: left;
  transition: transform .18s ease, box-shadow .18s ease, border-color .18s ease;
}
.study-concept-button:hover {
  transform: translateY(-2px); border-color: #f472b6; box-shadow: var(--shadow);
}
.study-concept-button-title { font-size: 1rem; font-weight: 800; color: #be185d; }
.study-concept-button-text { color: #475569; line-height: 1.5; font-size: .92rem; }
.study-concept-button-link { font-weight: 700; color: var(--primary); font-size: .9rem; }
.study-guide-grid {
  display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 20px; margin-bottom: 24px;
}
.study-list { padding-left: 20px; color: #334155; line-height: 1.7; }
.study-list li + li { margin-top: 10px; }
.study-list-numbered { padding-left: 24px; }
.study-concept-badge {
  display: inline-flex; align-items: center; justify-content: center; margin: 10px auto 0;
  padding: 6px 14px; border-radius: 999px; background: #e0e7ff; color: var(--primary);
  font-weight: 700; font-size: .88rem;
}
.study-paragraphs { display: flex; flex-direction: column; gap: 14px; }
.study-paragraphs p { color: #334155; line-height: 1.75; }
.study-example-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 16px;
}
.study-example-card {
  border: 2px solid #dbeafe; border-radius: 14px; background: #f8fbff; padding: 16px 18px;
}
.study-example-card h3 { color: var(--primary); font-size: 1rem; margin-bottom: 8px; }
.study-example-card p { color: #334155; line-height: 1.65; }

/* ══════════════════════════════════════
   QUIZ SCREEN
══════════════════════════════════════ */
#quiz-screen { display: flex; flex-direction: column; min-height: 100vh; }
#quiz-screen[hidden] { display: none; }

.quiz-header {
  display: flex; align-items: center; justify-content: space-between;
  background: var(--primary); color: #fff; padding: 12px 24px;
  position: sticky; top: 0; z-index: 100; box-shadow: 0 2px 8px rgba(0,0,0,.18);
}
.student-name { font-weight: 700; font-size: 1rem; max-width: 140px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.timer-wrap { display: flex; align-items: center; gap: 8px; }
.timer-display {
  font-size: 1.7rem; font-weight: 800; font-variant-numeric: tabular-nums;
  letter-spacing: 1px; transition: color .3s;
}
.timer-warn  .timer-display { color: #fde68a; }
.timer-danger .timer-display { color: #fca5a5; animation: pulse 1s infinite; }
@keyframes pulse { 0%,100%{ opacity:1; } 50%{ opacity:.6; } }

.progress-label { font-weight: 600; font-size: .95rem; }

.progress-bar-wrap { height: 6px; background: #e0e7ff; }
.progress-bar { height: 100%; background: var(--success); transition: width .4s ease; }

.quiz-main { flex: 1; display: flex; justify-content: center; padding: 28px 16px 10px; }
.question-card {
  background: var(--card-bg); border-radius: var(--radius); box-shadow: var(--shadow);
  padding: 32px 36px; max-width: 700px; width: 100%;
}
.question-meta { display: flex; gap: 10px; margin-bottom: 16px; }
.q-topic-badge {
  background: #e0e7ff; color: var(--primary); font-size: .78rem;
  font-weight: 700; padding: 3px 10px; border-radius: 20px; text-transform: uppercase;
}
.q-difficulty-badge { font-size: .78rem; font-weight: 700; padding: 3px 10px; border-radius: 20px; }
.diff-easy   { background: #dcfce7; color: #166534; }
.diff-medium { background: #fef9c3; color: #854d0e; }
.diff-hard   { background: #fee2e2; color: #991b1b; }
.diff-superhard { background: #ede9fe; color: #5b21b6; }

.question-text { font-size: 1.25rem; font-weight: 600; line-height: 1.6; margin-bottom: 28px; }

.options-container { display: flex; flex-direction: column; gap: 14px; }
.option-btn {
  display: flex; align-items: center; gap: 14px; width: 100%;
  padding: 14px 18px; border: 2px solid #e0e7ff; border-radius: 12px;
  background: #f8f9ff; font-size: 1.05rem; font-weight: 500; cursor: pointer;
  text-align: left; transition: all .18s; color: var(--text);
}
.option-btn:hover:not(:disabled):not(.selected):not(.correct):not(.incorrect) {
  border-color: var(--primary); background: #eef2ff;
}
.option-label {
  min-width: 30px; height: 30px; border-radius: 50%; background: #e0e7ff;
  color: var(--primary); font-weight: 800; font-size: .9rem;
  display: flex; align-items: center; justify-content: center; flex-shrink: 0;
}
.option-btn.selected { border-color: var(--primary); background: #eef2ff; }
.option-btn.selected .option-label { background: var(--primary); color: #fff; }

/* Results coloring */
.option-btn.correct   { border-color: var(--success); background: #f0fdf4; }
.option-btn.incorrect { border-color: var(--danger);  background: #fff1f2; }
.option-btn.correct   .option-label { background: var(--success); color: #fff; }
.option-btn.incorrect .option-label { background: var(--danger);  color: #fff; }
.option-btn:disabled { cursor: default; }

.quiz-footer {
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px 28px; background: #fff; border-top: 2px solid #e0e7ff;
  position: sticky; bottom: 0;
}
.answered-count { font-size: .92rem; color: var(--muted); font-weight: 600; }
.submit-row { text-align: center; padding: 10px 16px 20px; }

/* ── OVERLAYS ── */
.overlay {
  position: fixed; inset: 0; background: rgba(15,23,42,.55);
  display: flex; align-items: center; justify-content: center; z-index: 999;
}
.overlay[hidden] { display: none !important; }
.overlay-card {
  background: #fff; border-radius: 20px; padding: 40px 36px; max-width: 420px; width: 90%;
  text-align: center; box-shadow: 0 8px 40px rgba(0,0,0,.25);
}
.overlay-icon { font-size: 3.5rem; margin-bottom: 12px; }
.overlay-card h2 { font-size: 1.6rem; margin-bottom: 10px; }
.overlay-card p  { color: var(--muted); margin-bottom: 24px; }
.confirm-buttons { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }

/* ══════════════════════════════════════
   RESULTS SCREEN
══════════════════════════════════════ */
#results-screen { padding: 24px 16px 48px; }
.results-card { max-width: 780px; margin: 0 auto; }
.progress-card { max-width: 980px; }
.results-header { text-align: center; margin-bottom: 28px; }
.trophy { font-size: 4rem; }
.results-header h1 { font-size: 2rem; color: var(--primary); margin: 8px 0 4px; }
.results-name { font-size: 1.1rem; color: var(--muted); }

.score-circle-wrap { display: flex; align-items: center; justify-content: center; gap: 32px; flex-wrap: wrap; margin-bottom: 32px; }
.score-circle {
  width: 140px; height: 140px; border-radius: 50%; border: 8px solid var(--primary);
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  background: #eef2ff;
}
.score-pct { font-size: 2rem; font-weight: 800; color: var(--primary); }
.score-label { font-size: .8rem; color: var(--muted); font-weight: 600; }

.score-stats { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; }
.stat-box {
  display: flex; flex-direction: column; align-items: center; gap: 4px;
  background: var(--card-bg); border-radius: 12px; padding: 14px 20px;
  font-size: 1.5rem; font-weight: 800; box-shadow: var(--shadow); min-width: 90px;
}
.stat-box small { font-size: .75rem; font-weight: 600; color: var(--muted); }
.correct-box { border-top: 4px solid var(--success); }
.wrong-box   { border-top: 4px solid var(--danger); }
.skip-box    { border-top: 4px solid var(--muted); }
.time-box    { border-top: 4px solid var(--primary); }

.topic-breakdown, .review-section { background: var(--card-bg); border-radius: var(--radius); box-shadow: var(--shadow); padding: 24px 28px; margin-bottom: 24px; }
.topic-breakdown h2, .review-section h2 { font-size: 1.3rem; margin-bottom: 16px; color: var(--primary); }

.topic-row { display: flex; align-items: center; gap: 12px; margin-bottom: 12px; }
.topic-name { width: 170px; font-size: .9rem; font-weight: 600; flex-shrink: 0; }
.topic-bar-wrap { flex: 1; height: 14px; background: #e0e7ff; border-radius: 20px; overflow: hidden; }
.topic-bar { height: 100%; border-radius: 20px; background: var(--primary); transition: width 1s ease; }
.topic-score-text { font-size: .85rem; font-weight: 700; color: var(--muted); min-width: 60px; text-align: right; }

.review-item {
  border: 2px solid #e0e7ff; border-radius: 12px; padding: 16px 18px; margin-bottom: 14px;
}
.review-item.review-correct { border-color: #86efac; background: #f0fdf4; }
.review-item.review-wrong   { border-color: #fca5a5; background: #fff1f2; }
.review-item.review-skip    { border-color: #d1d5db; background: #f9fafb; }
.review-q  { font-weight: 600; margin-bottom: 8px; font-size: .95rem; }
.review-meta { font-size: .85rem; color: var(--muted); }
.review-meta span { margin-right: 14px; }

.results-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; margin-top: 8px; }

#progress-screen { padding: 24px 16px 48px; }
.parent-summary-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 14px; margin-bottom: 24px;
}
.summary-card {
  background: var(--card-bg); border-radius: 14px; box-shadow: var(--shadow);
  padding: 18px 16px; display: flex; flex-direction: column; gap: 6px; text-align: center;
}
.summary-value { font-size: 1.65rem; font-weight: 800; color: var(--primary); }
.summary-label { font-size: .82rem; color: var(--muted); font-weight: 600; }
.parent-overview-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 12px; }
.overview-pill {
  background: #eef2ff; border: 1px solid #c7d2fe; border-radius: 12px;
  padding: 14px 16px; display: flex; flex-direction: column; gap: 4px;
}
.overview-pill strong { color: var(--primary); font-size: .92rem; }
.overview-pill span { color: var(--text); font-weight: 600; }
.parent-empty { text-align: center; }
.parent-empty p { color: var(--muted); margin: 0; }
.history-list { display: flex; flex-direction: column; gap: 12px; }
.history-item {
  border: 2px solid #e0e7ff; border-radius: 12px; background: #f8f9ff;
  padding: 16px 18px; display: grid; grid-template-columns: minmax(180px, 1.2fr) repeat(3, minmax(90px, auto));
  gap: 10px; align-items: center;
}
.history-main { display: flex; flex-direction: column; gap: 4px; }
.history-title { font-weight: 700; color: var(--text); }
.history-subtitle { font-size: .84rem; color: var(--muted); }
.history-score, .history-time, .history-meta {
  font-weight: 700; color: var(--primary); text-align: right;
}
.history-time, .history-meta { color: var(--muted); font-size: .9rem; }

/* ══════════════════════════════════════
   DRAWING PAD (Rough Work)
══════════════════════════════════════ */
.quiz-main {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  height: calc(100vh - 180px);
}

.quiz-left-side {
  flex: 1;
  min-width: 0;
  overflow-y: auto;
}

.quiz-right-side {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 8px;
  background: white;
  border-radius: 12px;
  padding: 12px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}

.drawing-pad-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: 8px;
  border-bottom: 2px solid #e5e7eb;
}

.drawing-pad-header h3 {
  margin: 0;
  font-size: 1rem;
  color: #4f46e5;
  font-weight: 700;
  white-space: nowrap;
}

.drawing-header-tools {
  display: flex;
  gap: 4px;
  align-items: center;
}

.drawing-canvas {
  flex: 1;
  border: 2px solid #e5e7eb;
  border-radius: 8px;
  background: white;
  cursor: crosshair;
  touch-action: none;
  width: 100%;
  height: 100%;
  min-height: 400px;
}

.btn-icon-small {
  padding: 5px 10px;
  background: #f3f4f6;
  border: 1px solid #d1d5db;
  border-radius: 6px;
  cursor: pointer;
  font-size: 0.8rem;
  font-weight: 600;
  color: #374151;
  transition: all 0.18s ease;
}

.btn-icon-small:hover {
  background: #e5e7eb;
}

.btn-size-active {
  background: #4f46e5;
  color: white;
  border-color: #4f46e5;
}

/* ── RESPONSIVE ── */
@media (max-width: 1024px) {
  .quiz-main {
    gap: 8px;
    height: calc(100vh - 160px);
  }
  .drawing-tools {
    gap: 4px;
  }
}

@media (max-width: 768px) {
  .study-guide-grid {
    grid-template-columns: 1fr;
  }
  .study-visual-panel-full {
    padding: 16px;
  }
  .study-concept-grid, .study-example-grid {
    grid-template-columns: 1fr;
  }
  .quiz-main {
    flex-direction: column;
    height: auto;
    gap: 12px;
  }
  .quiz-left-side {
    min-height: 400px;
  }
  .quiz-right-side {
    width: 100%;
    min-height: 350px;
  }
  .drawing-canvas {
    min-height: 300px;
  }
}

@media (max-width: 600px) {
  .setup-card { padding: 28px 20px; }
  .question-card { padding: 20px 18px; }
  .question-text { font-size: 1.1rem; }
  .quiz-header { padding: 10px 14px; }
  .timer-display { font-size: 1.4rem; }
  .form-row { flex-direction: column; }
  .topic-name { width: 130px; font-size: .8rem; }
  .study-topic-button { padding: 16px; }
  .quiz-main {
    gap: 8px;
  }
  .quiz-left-side {
    min-height: 300px;
  }
  .quiz-right-side {
    min-height: 250px;
  }
  .drawing-canvas {
    min-height: 200px;
  }
  .history-item { grid-template-columns: 1fr; text-align: left; }
  .history-score, .history-time, .history-meta { text-align: left; }
}